EUASTRUM. 1 05 



biundulate, the l>as;il crense most prominent, obtuse, and an- 

 gle obliquely truncate; tumors three, inconspicuous and some- 

 times wanting; end view subelliptic, sides bigibbus ; side view 

 ovate. Membrane finely punctate. 

 Diameter 32-38 ft. 

 Rather common. 



E. CRASSICOLLE, Lund. Plate XXVII, figs. 37, 38. 



About twice as long as wide. Sinus narrow linear. Semi- 

 cells slightly attenuated, three lobed lateral lobes, lightly 

 sinuate-bilobulate ; polar lobe broad, barely diluted, apex 

 emarginate; end view hexagonal, poles truncate, middle 

 inflated. 



Diameter 11;/; length, 28 //. 



New Jersey net frequent. 



E. cuspiDATTJM, Wolle. Plate XXVII, fig. 32. 



I Kameter slightly less than length ; semicells distinctly three 

 lobed, basal lobes extending laterally their own width ; end 

 lobe subrectangular, twice the width of the other lobes, ob- 

 tusely sinuate in the centre ; ends of the rounded basal lobes 

 and of the two sections of the end lobe, surmounted each with 

 three firm, diverging, aculei. 



Diameter without aculei "Jo //.; with them 33 ft. 



Pond, Absecom, N. J. Coll., H. 1). Kit.hell, 1882. 



E. PINGUE, Elf. Plate XXVII, figS. 1, 2. 3. 



Somewhat longer than broad; semicells three lobed, each 

 lobe globularly rounded; the polar lobe with a small notch ; 

 side view oval with ends slightly truncate-crenate ; end and 

 side view show- a slight central inflation of semicells. [sthmus 

 about one-fourth the diameter of the cell. 



Diameter 35-45 //. 



Ponds, Atlantic and Passaic Counties, N. J. Our plants 

 are often without the terminal notch, but otherwise so near 

 the form described by Elfving, I adopt the name he has given. 



E. Xordstedtiaxum, Wolle. Plate XXVI, figs. 7, 9-13 ; and 

 Plate LII, figs. 13-15. 

 Cells quadrangular-oblong, not quite twice as long as broad ; 

 semicells obscurely three lobed ; basal lobes broad, each 



